1. Field of the Invention
The present invention relates to a connector, and especially to a modular jack designed to prevent improper insertion of a smaller sized plug connector.
2. Description of the Related Art
A modular jack is usually provided with an anti-mismating member for preventing an improper insertion of undersized plugs. U.S. Pat. No. 6,186,835 B1 issued to Cheshire on Feb. 13, 2001 discloses a modular jack for preventing incorrect insertions of smaller sized plugs. The modular jack comprises an insulative housing and an anti-mismating member integrally formed in a jack cavity of the housing. The anti-mismating member is composed of a flexible ramp projecting into an entry of the jack cavity. The ramp has an inner movable end with a vertical barrier. An inserted undersized plug is too small to touch the flexible ramp and thus fails to downwardly deflect the vertical barrier. As a result, the vertical barrier remains in its stopping position. The inserted undersized plug is blocked by the vertical barrier. When a full-sized plug is inserted into the modular jack, the full-sized plug engages with the ramp, riding along and downwardly deflecting the flexible ramp, making the vertical barrier move away a stopping position thereof, allowing full-sized inserted plug to be fully seated in the jack cavity. However, the anti-mismating member is made from plastic material and tends to lose flexibility after repeated use. Moreover, a large force exerted by the anti-mismating member is required to allow the fully insertion of the full-sized plug. The anti-mismating member is susceptible to damage or fracture on the housing, resulting in a short life-span.
U.S. Pat. No. 6,296,528 B1 issued to Roberts et al on Oct. 2, 2001 disclosed another conventional modular jack. The modular jack comprises an insulative housing defining a plug-receiving cavity and a pair of anti-mismating members received in the insulative housing. Each anti-mismating member comprises a sliding surface and a stop surface attached to an inner side of the sliding surface. The stop surface is provided for blocking an undersized plug being inserted. When a mating plug is inserted into the cavity, an upper surface of the mating plug contacts the sliding surface before reaching the stop surface and rides along the sliding surface, which causes the sliding surface to upwardly move. The movement produces a corresponding movement in the anti-mismating member and the stop surface thereon such that the stop surface is displaced out of a stop position, permitting full insertion of the mating plug into the cavity. When an undersized plug is inserted into the cavity, an upper surface of the undersized plug contacts the stop surface, preventing full insertion of the undersized plug into the cavity. However the pair of anti-mismating members are made separately and have to be separately assembled to the modular jack. Too more constituent parts produce an incompact frame resulting in a complicated assembling process.